1. 23 9月, 2016 1 次提交
  2. 26 6月, 2016 1 次提交
    • E
      net_sched: drop packets after root qdisc lock is released · 520ac30f
      Eric Dumazet 提交于
      Qdisc performance suffers when packets are dropped at enqueue()
      time because drops (kfree_skb()) are done while qdisc lock is held,
      delaying a dequeue() draining the queue.
      
      Nominal throughput can be reduced by 50 % when this happens,
      at a time we would like the dequeue() to proceed as fast as possible.
      
      Even FQ is vulnerable to this problem, while one of FQ goals was
      to provide some flow isolation.
      
      This patch adds a 'struct sk_buff **to_free' parameter to all
      qdisc->enqueue(), and in qdisc_drop() helper.
      
      I measured a performance increase of up to 12 %, but this patch
      is a prereq so that future batches in enqueue() can fly.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      520ac30f
  3. 01 3月, 2016 2 次提交
  4. 28 8月, 2015 1 次提交
    • D
      net: sched: consolidate tc_classify{,_compat} · 3b3ae880
      Daniel Borkmann 提交于
      For classifiers getting invoked via tc_classify(), we always need an
      extra function call into tc_classify_compat(), as both are being
      exported as symbols and tc_classify() itself doesn't do much except
      handling of reclassifications when tp->classify() returned with
      TC_ACT_RECLASSIFY.
      
      CBQ and ATM are the only qdiscs that directly call into tc_classify_compat(),
      all others use tc_classify(). When tc actions are being configured
      out in the kernel, tc_classify() effectively does nothing besides
      delegating.
      
      We could spare this layer and consolidate both functions. pktgen on
      single CPU constantly pushing skbs directly into the netif_receive_skb()
      path with a dummy classifier on ingress qdisc attached, improves
      slightly from 22.3Mpps to 23.1Mpps.
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3b3ae880
  5. 19 8月, 2015 1 次提交
  6. 04 5月, 2015 1 次提交
  7. 30 9月, 2014 1 次提交
  8. 14 9月, 2014 2 次提交
  9. 15 1月, 2014 1 次提交
  10. 12 7月, 2012 1 次提交
  11. 02 4月, 2012 1 次提交
  12. 10 2月, 2012 1 次提交
  13. 07 2月, 2012 1 次提交
  14. 29 11月, 2011 1 次提交
  15. 27 8月, 2011 1 次提交
  16. 24 2月, 2011 1 次提交
    • E
      net_sched: SFB flow scheduler · e13e02a3
      Eric Dumazet 提交于
      This is the Stochastic Fair Blue scheduler, based on work from :
      
      W. Feng, D. Kandlur, D. Saha, K. Shin. Blue: A New Class of Active Queue
      Management Algorithms. U. Michigan CSE-TR-387-99, April 1999.
      
      http://www.thefengs.com/wuchang/blue/CSE-TR-387-99.pdf
      
      This implementation is based on work done by Juliusz Chroboczek
      
      General SFB algorithm can be found in figure 14, page 15:
      
      B[l][n] : L x N array of bins (L levels, N bins per level)
      enqueue()
      Calculate hash function values h{0}, h{1}, .. h{L-1}
      Update bins at each level
      for i = 0 to L - 1
         if (B[i][h{i}].qlen > bin_size)
            B[i][h{i}].p_mark += p_increment;
         else if (B[i][h{i}].qlen == 0)
            B[i][h{i}].p_mark -= p_decrement;
      p_min = min(B[0][h{0}].p_mark ... B[L-1][h{L-1}].p_mark);
      if (p_min == 1.0)
          ratelimit();
      else
          mark/drop with probabilty p_min;
      
      I did the adaptation of Juliusz code to meet current kernel standards,
      and various changes to address previous comments :
      
      http://thread.gmane.org/gmane.linux.network/90225
      http://thread.gmane.org/gmane.linux.network/90375
      
      Default flow classifier is the rxhash introduced by RPS in 2.6.35, but
      we can use an external flow classifier if wanted.
      
      tc qdisc add dev $DEV parent 1:11 handle 11:  \
              est 0.5sec 2sec sfb limit 128
      
      tc filter add dev $DEV protocol ip parent 11: handle 3 \
              flow hash keys dst divisor 1024
      
      Notes:
      
      1) SFB default child qdisc is pfifo_fast. It can be changed by another
      qdisc but a child qdisc MUST not drop a packet previously queued. This
      is because SFB needs to handle a dequeued packet in order to maintain
      its virtual queue states. pfifo_head_drop or CHOKe should not be used.
      
      2) ECN is enabled by default, unlike RED/CHOKe/GRED
      
      With help from Patrick McHardy & Andi Kleen
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      CC: Juliusz Chroboczek <Juliusz.Chroboczek@pps.jussieu.fr>
      CC: Stephen Hemminger <shemminger@vyatta.com>
      CC: Patrick McHardy <kaber@trash.net>
      CC: Andi Kleen <andi@firstfloor.org>
      CC: John W. Linville <linville@tuxdriver.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e13e02a3
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